Surge Protection – Why?

18th Edition and surge protection

Now with the 18th Edition of the IET Wiring Regulations all electrical contractors will have to become familiar with surge protection devices. The Surge protection devices (SPDs) are designed to prevent electric shock and having excess voltage damaging the installation’s wiring infrastructure. So Should an over-voltage event occur (i.e switching events or lightning strikes for example), the SPD will divert the excess current flow to Earth.

Regulation 443.4 requires, (except for single dwelling units where the total value of the installation and equipment does not justify such protection).

When should surge protection be fitted?

For all other installations a risk assessment should be carried out to determine whether SPDs should be installed. Where a risk assessment is not carried out, then SPDs should be installed as a insurance policy to prevent any risk associated with transient over-voltages.

This is something contractors have not previously had to consider, This new regulation will need to be taken account of both in terms of time as well as cost add-ons for the customer. Any electronic devices that most household are now dependent on may be vulnerable to transient over-voltages, which can be caused by lightning strikes or a switching event. This creates a voltage spike increasing the voltage to potentially thousand’s of volts. This could cause alot of damage beyond repair to all devices pluged in via the mains. The extra cost to install a SPD would be justified compared to the cost of replacing all of the household electronic devices in the event of a power surge.

The need for SPDs will depend on many differing factors. These include the level of exposure of a building to lightning-induced voltage transients, the sensitivity and value of the equipment used within the building.

The shift in responsibility of risk assessment is now falling on the contractor. So it is now time to read up and fully understand the new regulations.

We as a Electrical wholesaler are reading and speaking to the manufactures about all the new changes we are seeing across the industry. We now stock a few different surge protection devices at Blackwater Electrical Supplies so pop in to see whats on offer.

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